kernel test robot lkp@intel.com writes:

All warnings (new ones prefixed by >>):

...

...

kernel/bpf/core.c:3037:13: warning: no previous prototype for 'bpf_jit_bypass_spec_v1' [-Wmissing-prototypes]

3037 | bool __weak bpf_jit_bypass_spec_v1(void)
     |             ^~~~~~~~~~~~~~~~~~~~~~

...

...

kernel/bpf/core.c:3042:13: warning: no previous prototype for 'bpf_jit_bypass_spec_v4' [-Wmissing-prototypes]

3042 | bool __weak bpf_jit_bypass_spec_v4(void)
     |             ^~~~~~~~~~~~~~~~~~~~~~

That's because the prototypes in include/linux/bpf.h were in the #ifdef CONFIG_BPF_SYSCALL. I fixed this for v3 by moving the prototypes out of the ifdef.